Off-by-One Out-of-Bounds Vulnerability in RTKLIB by Tomoji Takasu
CVE-2026-56787

6.9MEDIUM

Key Information:

Vendor

Tomojitakasu

Status
Rtklib
Vendor
CVE Published:
25 June 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-56787?

RTKLIB versions up to 2.4.3 are susceptible to an off-by-one out-of-bounds read vulnerability, specifically within the decode_ssr3 function. This issue permits remote attackers to instigate a global buffer overflow by transmitting specially crafted RTCM3 SSR messages that include manipulated signal mode fields. By leveraging this vulnerability, malicious actors can disrupt RTKLIB operation, leading to potential denial of service or crash scenarios for both RTKLIB rovers and CORS servers. Effective mitigation strategies are critical to ensure the integrity and availability of systems using RTKLIB.

Affected Version(s)

RTKLIB 0 <= 2.4.3

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-56787 - Proof of Concept

References

https://github.com/tomojitakasu/RTKLIB/issues/798
technical-descriptionexploit
https://www.vulncheck.com/advisories/rtklib-off-by-one-ou...
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

FuzzingLabs
.